1. Technical Field
The present disclosure generally relates to a manufacture used by a capping system for providing impermeable cover for land reclamation, and more particularly relates to a manufactured composite having synthetic grass and impermeable geo-membrane, as well as a capping system using the manufactured composite to provide permanent, impermeable and functional aesthetic cover for land reclamation.
2. Description of the Related Art
Synthetic turf has been extensively used not only for outdoor and indoor sports venues, but also in residential and a wide variety of commercial landscape applications, particularly in arid locations and/or regions where maintenance and water costs have risen. Before the emergence and wide use of synthetic turf, a typical capping system for land reclamation used, inter alia, natural grass, multiple layers of soil, synthetic drainage components and a layer of impermeable thermoplastic geomembrane (such as HDPE or LLDPE liners), to cap the waste there-below. With the advancement of synthetic turf over the past 50 years, capping systems have recently advanced to use, inter alia, synthetic turf and sand infill, rather than the previously used natural grass and top soil, along with separate layers of synthetic drainage components and impermeable thermoplastic geo-membrane liners.
U.S. Pat. No. 7,682,105 (hereinafter referred to as “the '105 patent”) discloses such a conventional synthetic grass capping system, which is illustrated in FIGS. 1A and 1B. As shown, capping system 100 uses separate layers. The top layer is synthetic turf formed of artificial grass 103 and geotextiles 104. A sand layer 105 of about 0.5 to about 1.0 inches is placed as infill of the synthetic turf to ballast the material and protect the system against wind uplift. Below geotextiles 104 of the synthetic turf is an impermeable LLDPE geomembrane 102 (which is also referred to as “Super GripNet” using the trademark of AGRU America, Inc.) having a series of spaced studs attached to the upside thereof and a series of spikes attached to the underside thereof. As disclosed in the '105 patent, the series of studs are incorporated in the impermeable liner part of LLDPE geomembrane 102 to form synthetic drainage components. Impermeable LLDPE geomembrane 102 covers foundation soil (also referred to as “intermediate soil cover”) 101, which caps and seal waste 108 situated there-below. In some conventional synthetic grass capping systems, there may be a gas collection layer (not shown) placed between thermoplastic geomembrane 102 and foundation soil 101.
Such conventional synthetic grass capping systems share a few common characteristics. First, such capping systems, as exemplified in FIGS. 1A and 1B by the one disclosed in the '105 patent, all require multiple distinct and separate layers each requiring a distinct and separate installation. For example, synthetic turf, sand infill and thermoplastic geomembrane are separate layers each requiring distinct and separate installations.
Next, such conventional synthetic grass capping systems, especially when being implemented on slopes, rely on heavy sand infill for anchoring against wind uplift. This is quite evident for capping system 100 of the '105 patent. In particular, capping system 100 prefers a sand layer of about 0.5 to about 1.0 inches (placed as infill), which, according to the '105 patent, produces a weight of about 5 to about 10 pounds per square foot, to ballast the material and protect capping system 100 against wind uplift. Moreover, as extensively detailed in the '105 patent, capping system 100 at least partly relies on the friction between the sand infill and the artificial grass layer to resist sliding failure when the capping system is implemented along steep slopes. Thus, having sand infill is essential for conventional synthetic grass capping systems like the capping system 100 disclosed in the '105 patent.
Further, in addition to basic synthetic turf and thermoplastic geomembrane liners, such conventional synthetic grass capping systems also require some forms of synthetic drainage components situated between an upper synthetic turf and a lower impermeable thermoplastic geomembrane liner. For example, as shown in FIGS. 1A and 1B, the series of spaced studs incorporated in LLDPE geomembrane 102 are synthetic drainage components required by the capping system 100 of the '105 patent.
These common characteristics, however, result in several disadvantages. Specifically, since such a conventional synthetic grass capping system requires multiple distinct and separate layers each requiring a distinct and separate installation, extensive labor, equipment and time, and therefore cost, are thus needed to deploy such a system in, for example, permanently closing a reclamation site. Next, since such a conventional synthetic grass capping system relies on heavy sand infill, implementing such a system inevitably requires substantial materials, transportation and site manipulation. Besides, since required sand infill is susceptible to wind and water erosion, such a conventional synthetic grass capping system often requires replenishing and repositioning of the sand infill in order to maintain aesthetic and functional objective, thus incurring higher costs in long-term maintenance. Further, as noted, in addition to basic synthetic turf and thermoplastic geomembrane liners, such a conventional synthetic grass capping system also requires synthetic drainage components. Thus, such a capping system inevitably incurs additional cost associated with manufacturing and incorporating synthetic drainage components in the capping system, thereby increasing overall cost required.
Therefore, there is a need for a capping system that can address the above-discussed issues existed in conventional synthetic grass capping systems exemplified by the one disclosed in the '105 patent.